This is the prototype QuakeZure device for detecting P-Waves and notifying Azure backoffice.
The kit cost about USD 120 and would get cheaper in quantity. Organisations like Seeedstudio can take a concept built with the Grove prototyping kit I used and organise production engineering of a real product from a concept if volumes are sufficient.
I have been looking at other MEMS devices from Freescale, ST MIcroelectronics, Analog devices, Memsic plus a few others. The key issue is that as soon as you go beyond consumer grade accelerometers the price rapidly rises to several times the cost of the rest of the kit.
For a production system you would most probably use something like GHI G120 Module USD37.39 with a custom board with the necessary power supply, connectivity & sensors mounted on it.